This website gives you a list with about every google icon hosted on https://ssl.gstatic.com/images/icons/product/
All the icons are made by Google.
Tip: when you are going to use these icons on a website, please use the url given by this website, instead of downloading the image and reuploading it to your host. This way, when google updates an icon, it will also be updated on your website.
Website made by +Carlos Jeurissen.
Thanks to +François Beaufort.